From 638dd5f44e2e56bb60a6f9aacbb1b3c22844926f Mon Sep 17 00:00:00 2001 From: Tim Chase Date: Fri, 15 Feb 2019 14:44:24 -0600 Subject: [PATCH] zio_deadman_impl() fix and enhancement Add the zio_deadman_log_all tunable to print all zios in zio_deadman_impl(). Also, in all cases, display the depth of the zio relative to the original parent zio. This is meant to be used by developers to gain diagnostic information for hangs which don't involve fully set-up zio trees or are otherwise stuck or hung in an early stage. Reviewed-by: Olaf Faaland Reviewed-by: Brian Behlendorf Reviewed-by: loli10K Signed-off-by: Tim Chase Closes #8362 --- man/man5/zfs-module-parameters.5 | 16 ++++++++++++++++ module/zfs/zio.c | 23 ++++++++++++++--------- 2 files changed, 30 insertions(+), 9 deletions(-) diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5 index dc9fcc6b4..bdac6f3a7 100644 --- a/man/man5/zfs-module-parameters.5 +++ b/man/man5/zfs-module-parameters.5 @@ -2638,6 +2638,22 @@ to limit potential SLOG device abuse by single active ZIL writer. Default value: \fB786,432\fR. .RE +.sp +.ne 2 +.na +\fBzio_deadman_log_all\fR (int) +.ad +.RS 12n +If non-zero, the zio deadman will produce debugging messages (see +\fBzfs_dbgmsg_enable\fR) for all zios, rather than only for leaf +zios possessing a vdev. This is meant to be used by developers to gain +diagnostic information for hang conditions which don't involve a mutex +or other locking primitive; typically conditions in which a thread in +the zio pipeline is looping indefinitely. +.sp +Default value: \fB0\fR. +.RE + .sp .ne 2 .na diff --git a/module/zfs/zio.c b/module/zfs/zio.c index 9ca53490e..0dd63322f 100644 --- a/module/zfs/zio.c +++ b/module/zfs/zio.c @@ -62,6 +62,7 @@ const char *zio_type_name[ZIO_TYPES] = { }; int zio_dva_throttle_enabled = B_TRUE; +int zio_deadman_log_all = B_FALSE; /* * ========================================================================== @@ -1858,30 +1859,30 @@ zio_delay_interrupt(zio_t *zio) } static void -zio_deadman_impl(zio_t *pio) +zio_deadman_impl(zio_t *pio, int ziodepth) { zio_t *cio, *cio_next; zio_link_t *zl = NULL; vdev_t *vd = pio->io_vd; - if (vd != NULL && vd->vdev_ops->vdev_op_leaf) { - vdev_queue_t *vq = &vd->vdev_queue; + if (zio_deadman_log_all || (vd != NULL && vd->vdev_ops->vdev_op_leaf)) { + vdev_queue_t *vq = vd ? &vd->vdev_queue : NULL; zbookmark_phys_t *zb = &pio->io_bookmark; uint64_t delta = gethrtime() - pio->io_timestamp; uint64_t failmode = spa_get_deadman_failmode(pio->io_spa); - zfs_dbgmsg("slow zio: zio=%p timestamp=%llu " + zfs_dbgmsg("slow zio[%d]: zio=%p timestamp=%llu " "delta=%llu queued=%llu io=%llu " "path=%s last=%llu " "type=%d priority=%d flags=0x%x " "stage=0x%x pipeline=0x%x pipeline-trace=0x%x " "objset=%llu object=%llu level=%llu blkid=%llu " "offset=%llu size=%llu error=%d", - pio, pio->io_timestamp, + ziodepth, pio, pio->io_timestamp, delta, pio->io_delta, pio->io_delay, - vd->vdev_path, vq->vq_io_complete_ts, + vd ? vd->vdev_path : "NULL", vq ? vq->vq_io_complete_ts : 0, pio->io_type, pio->io_priority, pio->io_flags, - pio->io_state, pio->io_pipeline, pio->io_pipeline_trace, + pio->io_stage, pio->io_pipeline, pio->io_pipeline_trace, zb->zb_objset, zb->zb_object, zb->zb_level, zb->zb_blkid, pio->io_offset, pio->io_size, pio->io_error); zfs_ereport_post(FM_EREPORT_ZFS_DEADMAN, @@ -1896,7 +1897,7 @@ zio_deadman_impl(zio_t *pio) mutex_enter(&pio->io_lock); for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) { cio_next = zio_walk_children(pio, &zl); - zio_deadman_impl(cio); + zio_deadman_impl(cio, ziodepth + 1); } mutex_exit(&pio->io_lock); } @@ -1914,7 +1915,7 @@ zio_deadman(zio_t *pio, char *tag) if (!zfs_deadman_enabled || spa_suspended(spa)) return; - zio_deadman_impl(pio); + zio_deadman_impl(pio, 0); switch (spa_get_deadman_failmode(spa)) { case ZIO_FAILURE_MODE_WAIT: @@ -4865,4 +4866,8 @@ MODULE_PARM_DESC(zfs_sync_pass_rewrite, module_param(zio_dva_throttle_enabled, int, 0644); MODULE_PARM_DESC(zio_dva_throttle_enabled, "Throttle block allocations in the ZIO pipeline"); + +module_param(zio_deadman_log_all, int, 0644); +MODULE_PARM_DESC(zio_deadman_log_all, + "Log all slow ZIOs, not just those with vdevs"); #endif -- 2.40.0